# coding=utf-8

print([x * 2 for x in range(1, 10)])
print([(x * 2, y * 2) for x in range(1, 10) for y in range(1, 10)])
print([(x * 2, y * 2) for x in range(1, 10) if x % 2 == 0 for y in range(1, 10)])
print([(x * 2, y * 2) for x in range(1, 10) if x % 2 == 0 for y in range(1, 10) if y % 2 == 0])